I have 3 questions=
1) Can carbon be used to displace lead from its ore? Give a reason for your answer.
2) can carbon be used to displace aluminium from its ore? Give a reason for your answer.
3) write the word equation for the chemical reaction taken place in the blast furnace.
Answers
Answer:
1) yes
2)no
3) Fe2O3 + 3CO → 2Fe + 3CO
Explanation:
1) yes...........If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.
2) no............Metals such as zinc, iron and copper are present in ores as their oxides. Each of these oxides is heated with carbon to obtain the metal. The metal oxide loses oxygen, and is therefore reduced. ... Some metals, such as aluminium, are so reactive that their oxides cannot be reduced by carbon.
3) This reaction might be divided into multiple steps, with the first being that preheated blast air blown into the furnace reacts with the carbon in the form of coke to produce carbon monoxide and heat:
2 C(s) + O2(g) → 2 CO(g)[65]
The hot carbon monoxide is the reducing agent for the iron ore and reacts with the iron oxide to produce molten iron and carbon dioxide. Depending on the temperature in the different parts of the furnace (warmest at the bottom) the iron is reduced in several steps. At the top, where the temperature usually is in the range between 200 °C and 700 °C, the iron oxide is partially reduced to iron(II,III) oxide, Fe3O4.
3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g)[65]
At temperatures around 850 °C, further down in the furnace, the iron(II,III) is reduced further to iron(II) oxide:
Fe3O4(s) + CO(g) → 3 FeO(s) + CO2(g)[65]
Hot carbon dioxide, unreacted carbon monoxide, and nitrogen from the air pass up through the furnace as fresh feed material travels down into the reaction zone. As the material travels downward, the counter-current gases both preheat the feed charge and decompose the limestone to calcium oxide and carbon dioxide:
CaCO3(s) → CaO(s) + CO2(g)[65]
The calcium oxide formed by decomposition reacts with various acidic impurities in the iron (notably silica), to form a fayalitic slag which is essentially calcium silicate, CaSiO
3:[64]
SiO2 + CaO → CaSiO3[66][better source needed]
As the iron(II) oxide moves down to the area with higher temperatures, ranging up to 1200 °C degrees, it is reduced further to iron metal:
FeO(s) + CO(g) → Fe(s) + CO2(g)[65]
The carbon dioxide formed in this process is re-reduced to carbon monoxide by the coke:
C(s) + CO2(g) → 2 CO(g)[65]
The temperature-dependent equilibrium controlling the gas atmosphere in the furnace is called the Boudouard reaction:
2CO ⇌ CO2 + C